Welded grating



' p 1945. w. c. HEATH 2,334,303

WELDED GRATING Filed March 27, 1941 William cHeczzh INVENTOR ATTORNEY- .grating is considerably provided in the shearing I Patented Sept. 4, 1945 UNITED STATES PATENT OFFICE I I I William 0. Heath, Shorewood, Wis., assignor to A. 0. Smith Corporatio Milwaukee, Wis., a

corporation of New York Application March 27, 1941, Serial No. 885,478

(Cl. lea-s2) Y ftive bars. In this construction, the slots 4 and I 2 Claims.

This invention relates t5 welded grating and has been applied to the construction of grating for use in safety walks and the like.

The principal obiect of the invention is to provide a welded grating made up of parallel bars held-in spaced relation by a set of parallel cross bars integrally secured thereto, and which stronger and less costly than the mechanically interlocked type of grating heretofore used. v 1

One embodiment of the invention is illustrated in the accompanying drawing in which:

Figure l is a parts broken away; 7

Fig. 2 is a perspective view of a longitudinal bar for the grating; and

8. 3 is a perspective view of a cross bar for the grating. v Y

The grating comprises a series Of spaced parallel longitudinal bars I and a series of spaced parallel cross bars I.

, The bars I and 2 are constructed of sheet metal strips disposed on edge in the-same general-plane to present a common safety structure. The cross bars 2 tread on top of.- the if desired. When the bars are disposed at right angles it is easy to construct rec angular, sections of tread having convenient dimensions for use as Walks and the like.

The bars I and 2 this construction, the serrated upper edges are p ration and two bars are formed simultaneously without waste of metal from shearing.

The longitudinal bars I have vertical slots I cut downwardly from their upper edges and spaced longitudinally of the bars a distance equal to the spacing of the cross bars 2 to receive the latter. The slots 3 are slightly wider than the thickness of the cross bars for ease of assembly. any crevice due to the clearance usually being filled later with galvanizing,-

The grating is prefera ly constructed with the intermediate cross bars 2 of less depth than the longitudinal bars and with both bars slotted. In such construction the cross bars 2 preferably are of greater depth than the slots 8, and have their lower edges slotted as at l to receive the bars I.

The end cross bars I areof the same depth as the longitudinal bars I and the lower edges of the bars I have slots 6 cut therein to receive the longitudinal bars I at the crossings of the respecare preferablydiss posed at right angles to the longitudinal bars I, although they may be disposed at an acute angle are preferably sheared'in pairs from a single continuous strip of metal. In

will each be approximately one-half of the total depth of the respective cross bars, although any suitable ratio of depths may be employed.

The spacing of the cross bars longiti'ldinallv' of the structure will normally be greater than the distance between the longitudinal bars, since this provides a structure 'of suilicient strength and 01' good appearance.

In manufacturing the grating, after the respective bars are formed with their serrated perspective view of a grating with f edges, as previously referred to, they are stacked and the respective slots'l'land 6 milled in a group of them simultaneously. From there the bars pass to the assembly station where they are assembled into the grate, either by hand or by an automatic machiner After assembly, the grate passes through the welding machine where an electrode. is applied in contact with the upper edge of each cross bar 2 and an opposite electrode is applied in contact with the lower edges of the longitudinal bars I. A very light resistance welding current and light pressure is thereby applied acrossthe contacting surfaces at the bottoms of th slots 8, I and 0. No attempt is made to weld the parts at the sides of the slots and it has been found that a grating of fully sumcient strength. can be obtained without substantial mushing' of the parts together in welding causing extrusion of metal from the slots. By welding in a plane intermediate the upper and lower edges of the respective bars, all parts are enabled to carry their respective loads and stresses with greater freedom from eccentricity. The slotting of both longitudinal and cross bars provides an interlocked structure of great stiffness. 7

Following the 'welding operation the grating is usually pickled and then galvanized or otherwise suitabhr coated. The galvanizing tends to fill the I crevices at the side walls of the slots and provides a more rigid structure, as well as protecta ing the steel from rust.

- The method of making the grating is claimed in Patent No. 2,335,181, died April 30, 1942, issued November 23, 1943.

The invention may have various embodiments within the scope of the accompanying claims.

I claim:

1. A welded grating comprising aseries of laterally spaced parallel longitudinal bars of strip metal vertically disposed on edge with their upper edge surfaces lying in substantially the same horizontal plane provide a common tread, a

series of spaced parallel cross bars of strip metal similsrly disposed on edge with their upper surfaces iyin: in the general plane 0! said tread surface, said cross bars beinz disposed loosely in regularly spaced slots with vertical side walls extending downwardly from the upper edges of said longitudinal bars, and welds Joining the bars only at the tint bottom of the respective slots near the mid-plane o! the structure and without extruaion or metal from the slots.

2. A welded gratingv comprisina' a series 0! laterally spaced parallel longitudinal bars of strip metal vertically disposed on edg with their upper edge surfaces lying in substantially the some horizontal plane to provide a common tread, a

series of spaced parallel cross bars 01 strip metal the mid-plane of similarlydlspoeedonedlewiththeirimper iaoeslyinginthegeneralpianeotsaidtreadsurhoe, said cross bars bein: disposed at the flat bottom the structure and without eltrusion of metal from the slots, and galvanizina material in the interstices between the vertical side walls of said slots and the respective ban W in slid slots to provide a rigid structure.

-WILLIAM C. HEATH. 

